Pneumatic player.



C. FREBORG.

PNEUMATIC PLAYER. APPLICATION men NOV. 18, 1913.

Patented July 17, 1917.

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C. FR EBORG. PNEUMATIC PLAYER. APPLICATION FILED NOV. 18. wrs.

Patented July 17, 1917.

2 S'HEETSSHEET 2- UNITED STATES PATENT @Fn E CHARLES FREBORG, OF KANKAKEE, ILLINOIS, ASSIGNOR TO PRICE AND TEEPLE PIANO COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

PNEUMATIC PLAYER.

Application filed November 18, 1913.

To all whom it may concern:

Be it known that I, CHAPLES FRnBoRe, a citizen of the United States, residing at Kankakee, in the county of Kankakee and State of Illinois, have invented certain new and useful Improvements in Pneumatic Players, of which the following is a specification.

The principal object of my invention is to provide a new and improved pneumatic player suitable for pianos. Another object of my invention is to provide an improved construction for the bleed-holes of a pneu matic player. Another object of my invention is to provide a bleed-hole construction that shall be simple and inexpensive to make, not liable to get out of order and rugged and serviceable in use. Another object of my invention relates to a guide for the button on the diaphragm that actuates the valve for each pneumatic of the player. All these objects and others will be made apparent in the following specification and claims, taken with the accompanying drawings, in which Figure 1 is a transverse section on the line 1, l of Fig. 4.

Fig. 2 is a section on the line 2, 2 of Fig. 4.

Fig. 3 is an elevation looking in the direction of the arrow 3 of Fig. 4, certain parts being broken away to show details of construction more clearly.

Fig. 4 is a plan view with certain parts broken away to exhibit the interior structure.

In these drawings I have illustrated one specific embodiment of my invention to enable me to explain its principle and mode of operation. It will be understood that the invention is defined in the appended claims. The apparatus shown in the drawings comprises part of the mechanism of a piano player. The vacuum chamber 6 extends substantially across the entire length of the piano. Along its floor there are conical depressions 7 entirely covered by loose leather diaphragms 8. Each cup 7 is connected by a conduit 9 to a rubber tube 10 which goes to a respectivehole of the tracker board. Above the vacuum chamber 6 is a series of valve chambers 11, each valve chamber 11 registering with a corresponding cup 7, and each valve chamber 11 being connected by Specification of Letters Patent.

Patented July 1'7, 1917.

Serial No. 801,607.

is a slender stem 19 which enters the short guide tube 20. This guide tube 20 is fitted tightly in the bottom wall of the vacuum chamber 6 and projects up into the conduit 9. A cap 21 is glued over the lower end of the tube 20 to keep the vacuum chamber airtight.

Extending along the length of the vacuum chamber 6 there is a square brass tube 22 with its upper wall a little thicker than the other walls. This tube 22 is connected at one end by a conduit 23 to the vacuum chamber 6. It is secured in place by a series of screws 24; which enter the rear member 25.

From the series of conduits 9 there are respective vertical branches 26 that go up and end along the under surface of the tube 22. Small holes 28 tapered to form valve seats are drilled in the lower wall of the tube 22 in register with the respective branch conduits 26 and needle valves 27 have screw threaded engagement through the upper wall of the tube 22 and seat on the respec tive valve seats 28. The upper wall of the tube 22 being thicker, makes it possible to get sufficient screw threaded engagement for the stems of the valves 27. The fit of these screw threads is made tight so that they will stay in adjustment.

hen the device is operating in a normal manner a partial vacuum is maintained in the vacuum chamber 6 and this same degree of vacuum is communicated through the branch passage 23 along the interior of the tube 22 and through the bleed-holes 28 and branches 26 of the conduits 9. Hence the diaphragins 8 have the same vacuum on their upper and under sides and therefore the parts, by their gravity and by the unbalanced force on valves 1%, take the positions shown in Fig. 1. When a hole of the tracker board is uncovered this permits atmospheric air to enter a tube 10 and raise the diaphragm 8; some of this air also enters the tube 22 through the bleed-hole 28, but not enough to unduly reduce the pressure in. the conduit 9. The raising of the diaphragm 8 raises the valve stem 15 and causes the valve 13 to close the valve chamber to the external air and opens the valve chamber 11 to com-' munication with the vacuum chamber 6; Therefore the air in the respective pneu matic rushes therefrom through the tube 12 under the valve 14 into the vacuum chamber 6. Accordingly the pneumatic collapses, which actuates the piano action.

The button 18' on the diaphragm 8 is con strained to move in a vertical path without angular change of position by reason of the stem 19 engaging the guide tube 20.. Thus even if it should. happen that the valve stem 15 rested a: trifleat one side of the center of the button 18, the valve stem 15 will be. definitely actuated nevertheless. If the guide members 19 and 20 were absent and if the valve stem 15 happened to rest on the button 18 alittle at one side of its center, the button 18 might tend to tilt and rise at one side only and. thus fail to actuate the valve stem 15. The mechanism that I have just described obviates this difiiculty.

Just before the hole in the tracker-board which connects with the tube 10 is closed the air in the conduit 9 is at atmospheric pressure. Immediately after such closure the continued flow of air from the conduit 9 through the branch passage 26" and bleedhole 2S-reduces the pressure inthe conduit 9 making it a partial vacuum This reduction of pressure inthe conduit 9 is communicated in like degree to the cup 7 and the reduction of pressure under the diaphragm 8 causes the diaphragm 8 to fall, and drops the stem 15 sothat the valve-13 opens the valve chamber 11' to the outsideair and the valve 1% closes the valve chamber 11 to the vacuum chamber 6. Thereupon the atmospheric air rushes in abovethe valve 13 and through the tube 12 to the pneumatic, infiating; the latter and restoring it to its normal condition. The bleed-hole opening. 28 should be adjusted in size with considerable precision. If it is opened too much, then the uncovering of the opening in the tracker board will not reduce the vacuum in the conduit 9 quickly enough to promptly actuate the diaphragm 8. On the other hand if the bleed-hole 28 is not opened enough, then when the tracker board opening is closed the restoration-of the vacuum in conduit 9 willnot occur quickly enough and the piano will not repeat properly.

One advantage of the bleed-holeconstruction that I have disclosed herein is that the branch 26 extends vertically up to thebleedhole. 28. Accordingly if any particles of dust or other foreign matter enter the tube 10 and the conduit 9 they will remain in the conduit. 9 rather than drift up the branch 26- and obstruct the bleed-hole 28; whereas if. the conduit 26 extended horizontally instead ofi vertically, the particles might lodge in it and obstruct the bleedshole.

Where bleed-holes are provided with adjustable valves and individual valve seat structures are made, the labor and expense involved are considerably greater than with my arrangement. I take the single tube 22 of brass or other material and drill the holes in the upper thick wall with a. gang drill. I. use drills with narrow points and run them. just far enough to cut the valve seats 2.8. Next I tap the holes in the upper extra thick Wall with screw threads and then apply the screw valves 27. Finally the? whole tube is fastened; in place with the screws 24. It will be seen that far less labor is involved than it individual valve seat structures were made and applied.

I claim:

1 1 In a pneumatic player, a vacuum. chamber,. a series of conduits communicating therewith from. the respective openings of the tracker board ,.branclies from. the respective conduits, and: a tube separate from the tracker boardand connected to the ends of said branches by respective bleed-holes, said tube being. located adjacent to and connected to said vacuum chamber.

2. Ina pneumatic player, a vacuum chamber, a series. of conduits communicating therewith from. the respective openings of the tracker boa-rd, parallel branches from the respective conduits adjacent said vacuum chamber, and a tube lying across the ends of said branch. conduits with respective bleed-holes through the wall of said tube connecting. the interior thereof with therespective branch conduits s aid tube being. directly connected adjacentv its ends to. said vacuum chamber.

3.. In apneumatic player,'.a vacuumchamber, a series of conduits communicating therewith from the respective openings of the tracker board, branchesext-ending vertically up from the respective conduits, a separate metal tube lying over the upper ends of said branches, said tube having bleed-holes in its wall connecting the interior thereof withv the respective branch conduits, and. said tube being connected to said vacuum chamber.

4. Ina pneumatic player, a vacuum chamber, a series of conduits communicating therewith from the respective openings of the tracker board, branches from the respective conduits, a separate metal" tube. independent of the tracker board lying across the ends- 0f said. branch conduitsrwith respective bleed holes through its side wall connecting with. the ends of said conduits, and screw valvespassing? through thewall of the tube opposite said bleed-holes, said valves being adapted to engage said bleedholes as valve seats.

5. In a pneumatic player, a vacuum chamber, a series of conduits communicating therewith from the respective openings of the tracker board, branches from the respective conduits, an integrally formed tube overlying the ends of said branches, said tube having transverse holes through its side walls alining in pairs, the holes on one side connecting with the said branch conduits and being tapered from valve seats and the holes on the opposite side being larger andoscrew threaded, and screw valves engaging said screw threaded holes and adapted to coact with the valve seats.

6. In a pneumatic player, a vacuum chamber, a series of conduits communicating therewith from the respective openings of the tracker board, said conduits extending for a certain distance across the bottom wall of the vacuum chamber, branch conduits therefrom extending vertically up through the rear wall of the chamber, and a long tube overlying the upper ends of said branch conduits, said tube having holes through its under side wall connecting with the branch conduits, and valves mounted in the tube to control said openings.

7 In a pneumatic player, a vacuum chamber, a series of conduits communicating therewith from the respective openings of the tracker board, said conduits extending for a certain distance across the bottom wall of the vacuum chamber, branch conduits therefrom extending vertically up through the rear wall of the chamber, a long tube of square cross section overlying the upper ends of said conduits, the under side wall of said tube having holes connecting with -1 said branch conduits, the upper wall of the tube being relatively thick, and screw valves extending transversely down through said upper thick wall having screw threaded engagen'ient therewith, said valves being adapted to control the openings in the lower side of the tube.

8. In a pneumatic player, a vacuum chamber, a series of conduits communicating therewith from the respective openings of the tracker board, branches from the respective conduits, and a tube connected to the ends of said branches by respective bleedholes, said tube being in permanent communication with said vacuum chamber.

9. In a pneumatic player, a vacuum chamber, a series of conduits communicating therewith from respective openings of the tracker board, vertically extending branches from the respective conduits, a tube overlying the upper ends of said branches with respective bleed-holes through the wall of said tube connecting the interior thereof with the respective branch conduits, and a short conduit directly connecting said tube with said vacuum chamber.

In testimony whereof, I have subscribed my name.

CHARLES FREBORG.

Witnesses:

FRANK BIRR, EDITH A. HoBsoN.

Copies of this patent ma; be obtained for five cents each, by addressing the Commissioner of Patents. Washington, I). G. 

